1. Field of the Invention
The present invention relates to an inverted telephoto type wide angle lens system having a relatively high aperture ratio of about 1/2.8, a relatively wide field angle reaching 84 degrees and a back focal length greater than the focal length of the lens system and more particularly to a lightweight and compact lens system.
2. Description of the Prior Art
Various different inverted telephoto type wide angle lens systems have been suggested such as those disclosed in U.S. Pat. Nos. 3,862,794 and 4,062,622. These patents respectively disclose state of the art embodiments.
The competitive rigors of the camera industry have placed a constant demand on the lens designers to provide ever increasing optical performances while further compacting and making lightweight lens systems. Accordingly, even though the prior art is crowded in attempts to achieve improved optical performance, there is still a demand to provide an improved inverted telephoto type wide angle lens system.